Hydrofining process



3,072,564 HYDROFINING PROCESS Frank Clyde Stewart, Jr., and HaroldDudley Dewhirst,

Baton Rouge, La., assignors to Esso Research and Engineering Company, acorporation of Delaware No Drawing. Filed Dec. 28, 1959, Ser. No.862,025 6 Claims. (Cl. 208-210) The present invention is concerned withthe production of light oils of the highest quality. More particularly,this invention pertains to the hydrofining of light distillate oils inorder to improve color and odor and reduce the aromaticity thereof.

The problem of refining and stabilizinglight distillate oils is adiflicult one. These oils are'widely used as lubrieating, diluent orsolvent oil in specialty services such as in textiles, and textileprocessing, disinfectants and sprays for household and agriculturalproducts. Numerous processes have been proposed for improving thequality of such light distillate oils such as extraction, clay treating,acid and caustic Washing, hydrogenation and hydrofining and combinationoperations involving hydrotreatficient improvement in the properties ofthe oil or the catalyst life of the more active catalysts has been tooshort to be commercially attractive. V

It is the object of this invention to provide a process for treatinglight distillate oils with hydrogen in the presence of a solid catalystto form products possessing excellent color, odor and stabilitycharacteristics.

It is also the object of this invention to prepare light distillate oilsof high color, low sulfur content and low aromaticity eminently suitablefor specialty services in textiles, disinfectants, sprays and the likeby a hydrofining treatment.

These and other objects will appear more clearly from the detailedspecification and claims which follow.

It has now been found that light distillate oils particularly suited forspecialty services can be prepared by hydrofining the same first at ahigh temperature to lower the sulfur content and reduce the aromaticityof the oil United States Patent Ofiice Patented Jan. 8, 1963Distillation (10 mm.):

P 200 (428) 5 300 (550) 10 312 (563) 50 333 (589) 95 360 (623) F.B.P.370 (635) sels or the second vessel may be provided with suitable heattransfer means to maintain the desired temperature in the second vessel.

The catalysts used for hydrofining light distillate oils in accordancewith this invention are cobalt molybdate or mixtures of cobalt oxide andmolybdenum oxide dispersed upon an alumina support or' carrier. Ingeneral, such catalysts are prepared by first forming aidsorptivealumina particles in any suitable way and then compositing molybdenumoxide and cobalt oxide therewith. The molybdenum oxide can be added as aslurry or as a solution of ammonium molybda te. 'Ihe cobalt oxide ismost conveniently added as a salt such as cobalt nitrate or acetate,salts which are readily decomposed to cobalt oxide and volatilematerials. The cobalt oxide and molybdenum oxide can be provided inequimolar amounts or a molecular excess of one over the other may beused. Suitable catalysts contain from about 5 to about 25 wt.

' percent of cobalt oxide and molybdenum oxide with the ratio of theformer to the latter in the range of from about one to five to aboutfive to one. Other catalysts which may be used include molybdenum oxideor sulfide Y on alumina containing about 5 to 15 wt. percent molybwith asuitable sulfiding agent such as hydrogen sulfide,

and then in a second stage at low temperatures for decolorization. Ithas been found that other hydrofining conditions being the same, colorimprovement decreases with increasing temperature and sulfur reductionand reduction in aromaticity increases with increasing tempera- Gravity,API 38.5 Flash, F 290 Color, Saybolt 14 Viscosity, SSU at 100 F 41Sulfur, Weight percent 0.26 Aniline point, F 182 carbon disulfide, ethylmercaptan, sour gas oil (1.0-3.0 wt. percent sulfur) or the like,preferably in the presence of hydrogen. The amount of sulfur added ispreferably at least 25% of the stoichiometric quantity necessary toconvert the catalytic metal oxides to the corresponding.

The hydrofining treatment is usually effected at pressures above about200 p.s.i.g., preferably at about 600 p.s.i.g. Higher pressures of up toabout 5000 p.s.i.g. can also be used but ordinarily the higher cost ofequipment to Withstand such pressures and the higher cost of operationat higher pressures makes it uneconomic to use pressures above about1000 p.s.i.g.

The temperature in the first hydrofining stage or pass is between about450 and 650 F., preferably at about 500550 F. The temperature in thesecond hydrofining stage or pass is between about l50250 R, preferablyabout 225 F. The feed rate ineach of the hydrofining stages is about /2to 4 v./v./hr., preferably about 2 v./v./hr. Hydrogen or hydrogen-richtreat gas .is supplied with the distillate oil feed at rates of from 50to 2000 s .c.f. per barrel of liquid feed, but preferably at a minimumrate of 300 s.c.f. per barrel of liquid feed for operating control. Thetreat gas should preferably contain at least 70 vol. percent ofhydrogen.

The following examples are illustrative of the present invention.

EXAMPLE 1 A non-phenol treated distillate oil produced by distween 150and 250 F. and at essentially the same pressure as in the first reactionzone.

2. The method for upgrading light distillate petroleum oils whichcomprises treating said oils in admixture with tilling a 40 SSU/100 F.stream from North Louisiana 5 f g f eg g g fi f fg figg g if??? crudewas treated with hydrogen in contact with 43" B 'ig g; i between 450 and5 F catalyst pills containing 2.43 wt. percent C and 9.86 3; 3 f g 400and 1,000 at feed wt. percent M00 dispersed on alumina. The catalyst t pf t Z d t l th was sulfided for 6 hours with a 1.4 wt. percent sulfur es2 o an Tea 3 6 Ion contgnt Sour gas oil at F 600 psi g and 10 1o turedischarged from the first reaction zone 1n contact The treatment waseffected at a pressure of with a cobalt ox1de-molybdenum oxide-aluminahydro- 600 at a feed rate of 2 VAL/hr. while charging fining catalyst attemperatures between 150 and 250 F. hydrogen treat gas at the rate of720 s.c.f./b. of liquid and at essentially the Same Pressure as in thefirst reacfeed. The catalyst in the form of 8 to 20 mesh particles tiOIl(mean particle size=12 mesh) was arranged in two 3. The method asdefined in claim 2 111 which the separate vessels each having an L/ Dratio of 90. temperature in the first reaction zone is about 500-550 Thereaction conditions and the results of these runs F. and the temperaturein the second reaction zone is are summarized in Table I. about 175-225F;

Table 1 Run No Spec. Feed 263 264 275 266 A a B i Hydrofiningconditions:

Pressure, p.s.i.g 600 600 600 600 600 600 600 600 600 Temperature, /F.,#1 reactor- 375 425 475 500 500 525 575 Temperature, F., #2 reactor. 275275 225 200 250 175 175 Feed rate, v.v./hr 2 2 2 2 2 2 Hi rate, s.c.t./b7 720 720 720 720 720 720 720 72c L/D ratio 90 90 90 90 90 90 90Inspections:

Gravity, API 38. 6 38. 39. 3 38. 6 38. 6 38. 5 38. 6 Flash, F- 280 280280 280 280 280 Fire. F- 320 310 310 310 315 305 v. 100, ssU 41 41 41 4141 41 Color, Saybolt"... +4 +9 +17 +18 29 +22 +22 Colorhold, Saybolt- 105 +16 +19 +19 Bromine number 1. 5 1. 8 1. 2 0. 4 1. 5 2.2 Aniline point,F 181.7 182.4 182.4 182. 8 197 182.4 182 8 Unsuliouated residue,percent- 3 90 90.0 90.0 89. 5 .0 90.0 91. 0 Corrosion, 3 hrs. at 212 F 4J5 J-3 4 0. 15 0. 26 0. 20 0.19 0.18 0.15 0. 02 0.14 0.12 Clo d, F 36 2628 30 2e 28 26 Alcoa stain test- D A A A Rating Fail Perfect Good GoodOdor (0 1 This run was made with a catalyst of the same composition froma different manufacturer. 9 Runs designated A and B represent;correlated values for higher temperature first stage operations to bringsulfur content below 0.15 max.

8 Minimum. 4 Maximum. 5 Borderline. Satisfactory.

EXAMPLE 2 A light distillate oil (Menton 28) was hydrofined in atwo-stage operation with cobalt molybdate-on-alumina catalyst. Thereaction conditions, feed and product inspections are summarized inTable II below.

The foregoing specification contains a limited number of embodiments ofthe present invention. It will be understood however, that numerousvariations are possible without departing from the scope of thisinvention.

What is claimed is:

1. The method for upgrading light distillate petroleum oils whichcomprises treating said oils in admixture with a hydrogen rich gas in afirst reaction zone in contact with a hydrofining catalyst attemperatures between 450 and 650 F. and pressures of between 400 and1000 p.s.i.g. at feed rates of /2 to 4 v./v./hr. and treating thereaction mixture discharged from the first reaction zone in contact witha hydrofining catalyst at temperatures be- 4. The method for upgradingpetroleum oils having an initial boiling point of at least 425 F. and anend point of about 700 P. which comprises treating said oils inadmixture with a hydrogen rich gas in a first reaction zone in contactwith a hydrofining catalyst at temperatures between 450 and 650 F. andpressures of between 400 and 1000 p.s.i.g. at feed rates of /z to 4v./v./hr. and treating the reaction mixture discharged from the firstreaction zone in contact with a hydrofining catalyst at temperaturesbetween and 250 F. and at essentially the same pressure as in the firstreaction zone.

5. The method for upgrading petroleum oils having an initial boilingpoint of at least 425 F. and an end point of about 700 F. whichcomprises treating said oils in admixture with a hydrogen rich gas in afirst reaction zone in contact with a cobalt oxide-molybdenumoxidealumina hydrofining catalyst at temperatures between 450 and 650 F.and pressures of between 400 and 1000 p.s.i.g. at feed rates of A2 to 4v./v./hr. and treating the reaction mixture discharged from the firstreaction zone in contact with a cobalt oxide-molybdenum oxidealuminahydrofining catalyst at temperatures between 150 and 250 F. and atessentially the same pressure as in the first reaction zone.

6. The method for upgrading light distillate petroleum oils boiling inthe range of about 425 F. to about 700 E, which comprises treating saidoils in admixture with a hydrogen-rich gas in a first reaction zone incontact with a cobalt oxide-molybdenum oxide hydrofining catalyst attemperatures between 500 and 550 F. and

References Cited in the file of this patent UNITED STATES PATENTS DorrerMay 3, 1938 Mason Feb. 14, 1950 Harper et a1 Apr. 12, 1955 Sweetser eta1. Nov. 6, 1956

1. THE METHOD FOR UPGRADING LIGHT DISTILLATE PETROLEUM OILS WHICHCOMPRISES TREATING SAID OILS IN ADMIXTURE WITH A HYDROGEN RICH GAS IN AFIRST REACTION ZONE IN CONTACT WITH A HYDROFINING CATALYST ATTEMPERATURES BETWEEN 450 AND 650*F. AND PRESSURES OF BETWEEN 400 AND1000 P.S.I.G. AT FEED RATES OF 1/2 TO 4 V./V./HR. AND TREATING THEREACTION MIXTURE DISCHARGED FROM THE FIRST REACTION ZONE IN CONTACT WITHA HYDROFINING CATALYST AT TEMPERATURES BETWEEN 150 AND 250*F. AND ATESSENTIALLY THE SAME PRESSURE AS IN THE FIRST REACTION ZONE.